[Technical Dive] How Piezas Checks the Design of Your Code

When you build an app with Piezas, your AI tool writes the code. Piezas checks that code at several points, so your app keeps your business data and your keys where they belong. This page explains what we check, when we check it, and what happens if something doesn't pass.

What we check for

Every Piezas app follows a short set of rules. These are the ones we check automatically:

• Business records live in Piezas. The app must not keep its own separate database for customers, bookings, invoices or other business records. A second copy that nothing else can see is how data goes missing or out of date.
• Your Piezas key stays on the server. The key that lets your app talk to Piezas must never be built into the pages people open in their browser. If it were, anyone visiting your app could copy it.
• Keys are never written into the code. Keys belong in your app's private settings, not in the code itself.
• Connections to other services stay in Piezas. When your app connects to services such as Google or Stripe, Piezas keeps the access passes for those services. Your app keeps only a reference to the connection.
• Only you approve the design. Your AI tool can show you the design, but only your own reply of "approve" moves the build forward.

Piezas sign-in uses a separate "publishable" key that is designed to be public, so that key is allowed in the browser.

When we check

We check at four points. Each one catches what an earlier one might miss.

1. While your app is being written. With the Piezas plugin in Claude Code or Codex, every change your AI tool makes is checked before it is saved. If a change would break a rule, it is stopped, and your AI tool is told why, so it can do it the right way instead. You will usually see one sentence about what was changed and why.
2. At the end of each reply. Before your AI tool finishes a reply, Piezas checks the whole app once more against the same rules.
3. At each step of the build. Moving from the design preview to building checks the rules again. If one is broken, that step waits until it is fixed.
4. When your app arrives on Piezas hosting. Every version you deploy is checked on our side before it goes live. This check cannot be switched off. If it finds a problem, Piezas pauses the deploy and tells you what is wrong. Your AI tool can usually fix it. If you still want that version live, you confirm by replying "deploy anyway". Only you can do this, not your AI tool, and we keep a record that you did.

What happens when something doesn't pass

Nothing is lost. While your app is being built, these rules are not optional: a change that breaks one is stopped, and your AI tool receives a plain explanation and fixes it, usually without needing anything from you.

At deploy, a problem pauses the deploy rather than failing it. The version that is already live keeps running until the problem is fixed or you confirm the new version.

If the checks are switched off

The checks at points 1 and 2 run inside your AI tool, so they stop if the Piezas plugin is turned off or if Node.js is not installed on your computer. When that happens, Piezas tells you that its safety checks are off and how to turn them back on. The checks at points 3 and 4 still run, and point 4 runs on Piezas whatever happens on your computer.

What we look at, and what we don't

• The checks at points 1 to 3 run on your own computer. Your code is not sent to Piezas for them.
• The check at point 4 looks only at the version of the app you deploy to Piezas hosting.
• We check for the rules above. We do not judge your design, your wording, or how you choose to build your features.

Common questions

My AI tool says a change was blocked. What should I do? Usually nothing. The message tells your AI tool what went wrong, and it fixes the problem itself. If it keeps happening, ask your AI tool to explain in plain words, or contact us.

A deploy paused. Should I reply "deploy anyway"? Usually not. Ask your AI tool to fix the problem first; it normally can, and it only takes a moment. Confirm only if you understand the risk described in the message and need that version live now.

Do these checks mean my app has no bugs? No. They cover the rules above, which protect your data and your keys. Whether the app does what you agreed is checked separately: each thing you agreed on gets an automatic test, and you can watch a short clip of each one working before you go live.

I think a check is wrong. Who do I tell? Email support@piezas.ai with your app's name and the message you saw. We read every report.